Audio test apparatus and test method thereof

Abstract

An audio test apparatus, and an exemplary audio test method that includes: processing an audio file through two independent channels; outputting no signals from a left channel and from a right channel in a first time period; receiving noise signals from the left and right channels; outputting single-frequency signals from the left channel only in a second time period; receiving the single-frequency signals from the left channel and crosstalk signals from the right channel; outputting multi-frequency signals from the left and right channels in a third time period; receiving the multi-frequency signals from the left and right channels; outputting single-frequency signals from the right channel only in a fourth time period; receiving the crosstalk signals from the left channel and the single-frequency signals from the right channel; and testing parameters according to the signals received during the four time periods.

1. An audio test apparatus, comprising:
 a storage unit storing a media test file, wherein the media test file is configured to be played through two independent channels, and the media test file comprises a first data section, a second data section, a third data section, and a fourth data section, wherein the first data section is configured for no signal output from the first channel and the second channel when processed, the second data section is configured for outputting single-frequency signals from the first channel and no signal output from the second channel when processed, the third data section is configured for outputting multi-frequency signals from the first channel and the second channel when processed, and the fourth data section is configured for outputting single-frequency signals from the second channel and no signal output from the first channel when processed; 
 an audio collection device configured for receiving the signals outputted from the first channel and the second channel and converting the signals into digital signals; and 
 a central processing unit (CPU) configured for storing the digital signals in the storage unit and performing a test according to the stored digital signals. 
 
     
     
       2. The audio test apparatus of  claim 1 , wherein the audio collection device is a sound card. 
     
     
       3. The audio test apparatus of  claim 1 , wherein the CPU is further configured for outputting test results to a display. 
     
     
       4. The audio test apparatus of  claim 1 , wherein the CPU is further configured for storing test results in the storage unit. 
     
     
       5. An audio test method comprising:
 processing a media test file through two independent channels; 
 outputting no signal from a first channel and from a second channel in a first time period; 
 receiving noise signals from the first channel and the second channel, converting the received signals into first channel digital noise signals and second channel digital noise signals, and storing the first channel digital noise signals and second channel digital noise signals in a storage unit; 
 outputting single-frequency signals from the first channel and outputting no signal from the second channel in a second time period; 
 receiving the single-frequency signals from the first channel and crosstalk signals from the second channel, converting the received signals into first channel digital single-frequency signals and second channel digital crosstalk signals, and storing the first channel digital single-frequency signals and second channel digital crosstalk signals in the storage unit; 
 outputting multi-frequency signals from the first channel and the second channel in a third time period; 
 receiving multi-frequency signals from the first channel and the second channel and converting the received signals into first channel digital multi-frequency signals and second channel digital multi-frequency signals, and storing the first channel digital multi-frequency signals and second channel digital multi-frequency signals in the storage unit; 
 outputting no signal from the first channel and outputting single-frequency signals from the second channel in a fourth time period; 
 receiving crosstalk signals from the first channel and single-frequency signals from the second channel, converting the received signals into first channel digital crosstalk signals and second channel digital single-frequency signals, and storing the first channel digital crosstalk signals and second channel digital single-frequency signals in the storage unit; and 
 performing a test according to the digital signals during the four time periods. 
 
     
     
       6. The audio test method of  claim 5 , further comprising at least one of:
 outputting test results to a display; and 
 storing test results in the storage unit. 
 
     
     
       7. The audio test method of  claim 5 , further comprising:
 computing a first channel noise level and a second channel noise level according to the first channel digital noise signals and the second channel digital noise signals stored during the first time period; 
 computing a first channel signal level according to the first channel digital single-frequency signals stored during the second time period and computing a second channel signal level according to the second channel digital single-frequency signals that stored during the fourth time period; and 
 calculating a signal to noise ratio (SNR) of both the first channel according to the first channel signal level and the first channel noise level and the second channel according to the second channel signal level and the second channel noise level. 
 
     
     
       8. The audio test method of  claim 5 , further comprising:
 computing the first channel signal level according to the first channel digital single-frequency signals stored during the second time period and computing a second channel crosstalk signal level according to the second channel digital crosstalk signals stored in the second time period; 
 computing the second channel signal level according to the second channel digital single-frequency signals stored during the fourth time period and computing a first channel crosstalk signal level according to the first channel digital crosstalk signals stored during the fourth time period; and 
 computing the crosstalk of the first channel according to the first channel crosstalk signal level and the first channel signal level and the crosstalk of the second channel according to the second channel crosstalk signal level and the second channel signal level. 
 
     
     
       9. The audio test method of  claim 5 , further comprising:
 converting the first channel digital single-frequency signals and the second channel digital single-frequency signals into frequency domain signals using a Fast Fourier Transform (FFT); 
 obtaining amplitudes of harmonic compositions of the first channel according to the first channel frequency domain signals and obtaining amplitudes of harmonic compositions of the second channel according to the second channel frequency domain signals; and 
 calculating the total harmonic distortion (THD) of the first channel according to the amplitudes of the harmonic compositions of the first channel and calculating the THD of the second channel according to the amplitudes of the harmonic compositions of the second channel. 
 
     
     
       10. The audio test method of  claim 5 , further comprising:
 computing the first channel signal level according to the first channel digital single-frequency signals and the second channel signal level according to the second channel digital single-frequency signals; and 
 comparing the first channel signal level and the second channel signal level with a predetermined signal level, and determining that Full Scale distortion exists if the difference between the first channel signal level and predetermined signal level or the difference between the second channel signal level and the predetermined signal level, exceeds a predetermined value. 
 
     
     
       11. The audio test method of  claim 5 , further comprising:
 intercepting a plurality of segments of the first channel digital multi-frequency signals and the second channel digital multi-frequency signals and converting the intercepted segments of the first channel digital multi-frequency signals and the second channel digital multi-frequency signals into frequency domain signals through FFT; 
 calculating an average first channel frequency domain signal and an average second channel frequency domain signal; and 
 
       calculating Frequency Response of the first channel and the second channel according to the average first channel frequency domain signal and the second channel frequency domain signal.